Orthopedic external fixation device

Abstract

A telescopically adjustable strut for use with orthopedic external fixators has a first end and a second end and includes a universal-hinged connector provided at each of the first and second ends for connecting the strut to orthopedic external fixator base members. The universal-hinged connector is configured and adapted for pivoting the strut relative to the base members and to lock the universal-hinged connector at a desired angle.

What is claimed is: 
     
       1. An orthopedic fixation system, comprising:
 a universal joint including
 a ball from which a stem having a terminal end extends; 
 a housing including a first portion and a second portion that together define a spherical internal volume that is sized and configured to receive the ball, the second portion including an elongate stem portion defining a hole that communicates with the spherical internal volume; and 
 a locking pin including an elongate shaft and an outer wall that defines an annular recess, the elongate shaft of the locking pin being sized and configured to be received within the hole defined by the elongate stem of the second portion of the housing, 
 
 wherein an internal portion of the outer wall of the locking pin includes threads for engaging threads disposed on a distal end of the elongate stem of the second portion of the housing, and 
 wherein a distal end of the elongate shaft of the locking pin is configured to contact the ball to generate a frictional interference to lock the universal joint. 
 
     
     
       2. The orthopedic system of  claim 1 , wherein the terminal end of the stem defines a hollow opening sized and configured to receive one of a lead screw or a shaft. 
     
     
       3. The orthopedic system of  claim 1 , further comprising a locking nut for locking the universal joint to a base member. 
     
     
       4. The orthopedic system of  claim 1 , further comprising a telescopically adjustable strut including
 an elongated shaft defining a hollow axial center, and 
 a lead screw having external threads, one end of the lead screw extending into the axial center of the shaft and the other end of the lead screw being coupled to the terminal end of the stem of the universal joint. 
 
     
     
       5. The orthopedic system of  claim 4 , further comprising a pair of ring-like base members and a locking nut, wherein the locking nut is configured to connect at least one of the ring-like base members to the second threaded stem portion of the universal joint. 
     
     
       6. The orthopedic system of  claim 5 , wherein the shaft defines a slot extending along a side of the shaft in the axial direction, and a projection is provided on the lead screw that extends into the slot, whereby the projection is visible through the slot and prevents axial rotation of the lead screw relative to the shaft. 
     
     
       7. The orthopedic system of  claim 6 , wherein the elongated shaft includes graduated marks provided along the slot, whereby the location of the projection relative to the graduated marks indicates the length of the strut, the length of the strut being defined by predetermined end points on the strut. 
     
     
       8. The orthopedic system of  claim 7 , further comprising an adjustable knob rotatably attached to one end of the elongated shaft, the adjustable knob defining an axially-oriented opening through which the lead screw extends and threadably engaging the external threads on the lead screw. 
     
     
       9. The orthopedic system of  claim 8 , wherein the external threads on the lead screw and the adjustment knob are pitched such that one or more complete revolution of the adjustment knob about the axis of the shaft causes the lead screw to axially translate a known incremental distance relative to the shaft. 
     
     
       10. An orthopedic fixation system, comprising:
 a universal joint including
 a first component including a ball and a stem; 
 a second component and a third component that when coupled together define a spherical internal volume that is sized and configured to receive the ball therein, the third component including an elongate portion defining a hole that communicates with the spherical internal volume; and 
 a fourth component including an elongate shaft and an outer wall that defines an annular recess, the elongate shaft being sized and configured to be received within the hole defined by the third component, 
 
 wherein an internal portion of the outer wall of the fourth component includes threads for engaging threads disposed on a distal end of the elongate portion of the third component, and 
 wherein a distal end of the fourth component is configured to contact the ball to generate a frictional interference to lock the universal joint. 
 
     
     
       11. The orthopedic fixation system of  claim 10 , wherein the outer wall of the fourth component is disposed at end of the elongate shaft of the fourth component. 
     
     
       12. The orthopedic fixation system of  claim 10 , further comprising a countersunk locking nut sized and configured to engage the outer wall of the fourth component. 
     
     
       13. The orthopedic fixation system of  claim 10 , further comprising a telescopically adjustable strut including
 an elonagated shaft defining a hollow axial center, and 
 a lead screw having external threads, one end of the lead screw extending into the axial center of the shaft of the telescopically adjustable strut and the other end of the lead screw being coupled to an end of the stem of the first component of the universal joint. 
 
     
     
       14. An orthopedic fixation system, comprising:
 a universal joint including
 a housing defining a spherical internal volume that is sized and configured to receive a ball therein, a first component of the housing including an elongate portion that defines a hole that extends through the elongate portion and communicates with the spherical internal volume; and 
 a locking pin including an elongate shaft and an outer wall disposed at one end of the elongate shaft, the elongate shaft being sized and configured to be received within the elongate portion of the first component of the housing to contact the ball, 
 
 wherein an internal portion of the outer wall of the locking pin includes threads for engaging threads disposed on a distal end of the elongate portion of the of the first component of the housing. 
 
     
     
       15. The orthopedic fixation system of  claim 14 , wherein the housing includes a second component that is configured to engage the first component of the housing via a threaded connection. 
     
     
       16. The orthopedic fixation system of  claim 14 , further comprising a locking nut for locking the universal joint to a base member. 
     
     
       17. The orthopedic fixation system of  claim 16 , wherein the locking nut defines an opening that is sized and configured to slide along an outer surface of the elongate portion of the first component.